reduce OP_ARRAY in argument splat

mrbgems/mruby-compiler/core/codegen.c

@@ -780,6 +780,11 @@ gen_values(codegen_scope *s, node *t, int val)
     is_splat = (intptr_t)t->car->car == NODE_SPLAT; /* splat mode */
     if (n >= 127 || is_splat) {
       if (val) {
+        if (is_splat && n == 0 && (intptr_t)t->car->cdr->car == NODE_ARRAY) {
+          codegen(s, t->car->cdr, VAL);
+          pop();
+        }
+        else {
           pop_n(n);
           genop(s, MKOP_ABC(OP_ARRAY, cursp(), cursp(), n));
           push();
@@ -791,6 +796,7 @@ gen_values(codegen_scope *s, node *t, int val)
           else {
             genop(s, MKOP_AB(OP_ARYPUSH, cursp(), cursp()+1));
           }
+        }
         t = t->cdr;
         while (t) {
           push();